Rationally designed dual cocatalysts on ZnIn2S4 nanoflowers for photoredox coupling of benzyl alcohol oxidation with H2 evolution

Abstract

Constructing a dual-functional reaction platform combining photocatalytic hydrogen evolution and selective organic synthesis is an effective approach for utilizing both photogenerated electrons and holes to obtain clean, renewable fuels and high-value chemicals. Herein, we synthesized a composite photocatalyst of nickel phosphide (Ni₂P) and graphene (GR) dual cocatalyst modified zinc indium sulfide (ZnIn₂S₄) for efficient photocatalytic oxidation of benzyl alcohol (BA) coupled with hydrogen production. In this dual co-catalyst system, GR as an electron relay station can accelerate electron transfer, and Ni₂P can facilitate the separation of photogenerated carriers in the composite while providing the active site for proton reduction. As a result, the ZnIn₂S₄–GR–Ni₂P composite exhibited significantly higher activity in the photocatalytic oxidation of benzyl alcohol (BA) coupled with hydrogen production than blank ZnIn₂S₄, ZnIn₂S₄–GR, and ZnIn₂S₄–Ni₂P. This study proposes a new method of combining dual cocatalysts with semiconductor photocatalysts to simultaneously utilize photo-induced electrons and holes for synergistic coupling of photocatalytic organic synthesis and hydrogen production.